1. Field of the Invention
The present invention relates generally to a camber, toe, and caster adjustment apparatus and method, and more particularly, to a camber adjustment apparatus and method for alignment of vehicle wheels.
2. Description of the Related Art
Camber angle, referred to as camber in the automotive trade, is the variance in degrees measured between true vertical and that of the measured vertical axis of a wheel. Camber, in combination with suspension design and other wheel alignment specifications, is tuned to meet a user's desired vehicle handling, performance and tire wear requirements. To keep a vehicle's wheels properly aligned for optimized handling, performance and tire wear attributes, wheel alignment is performed from time to time. In performance vehicles, proper camber is necessary as mis-alignment of camber leads to an increase in tire temperature at high speeds, especially in turns, making the tires more susceptible to damage due to improper contact with the ground and resulting in inadequate contact between the tire and the road.
In a race car pit, a user measures camber, toe and caster of a wheel and adjusts the vehicle's suspension to tune the wheel to the desired camber, toe, and caster while the vehicle is on the ground. The user then repeats camber, toe, and caster measurement and suspension adjustment for the other wheel on the same axle of the vehicle to match the desired camber, toe, and caster. The vehicle's wheel is generally removed to provide convenient access to the vehicle's suspension during adjustment. When the wheel is replaced, camber is again measured by the user to ensure that the adjustment achieved the desired camber, toe and caster.
Under non-racing conditions, the vehicle is placed on a hydraulic lift to perform camber adjustment. After the suspension is tuned, the wheel is reinstalled and the vehicle is lowered to the ground to measure camber of the wheels. Camber adjustment using this method generally leads to adjustment errors of 0.5-1.0 degrees in the negative or positive direction. Such an error in wheel alignment leads to a decline in vehicle handling, performance and tire wear. In performance vehicle usage under, for example, racing conditions, the vehicle cannot be placed on a hydraulic lift due to time constraints.
A conventional device used in the automotive arts for on-the-ground camber adjustment is known as a hub-stand. The hub-stand bolts onto a vehicle's wheel hub in place of a wheel and allows a user to adjust the vehicle's suspension. The hub-stand replaces the wheel, allowing for convenient access to the vehicle's suspension system, but includes no functionality related to correctly adjusting camber, toe and caster. Thus, when the wheel is reinstalled, the user experiences difficulty in having the same camber set-up as with the hub-stands installed.